Misconceptions With Controlled Release Fertilizers

Passchier: There are two factors involved when speaking about incorporation and topdressing the fertilizer. The first is the potential differences in nutrient availability for the plant when incorporating versus topdressing. The second is the amount of fertilizer that is used when incorporated compared to the topdressing rate.

Let’s remember that CRF fertilizers are released by temperature and research shows that different technologies are affected by the temperature changes around the CRF prill that can alter their expected release. Just think about the temperature fluctuations and moisture consistency in the media versus the temperature fluctuation and moisture consistency on top of the media. In general, there is likely to be less temperature fluctuation and more moisture consistency in the pot than on the surface of the pot.

The surface of the media is subject to greater temperature changes between night to day and from cloudy to sunny days. Growers can expect the release of incorporated fertilizers to be more consistent than fertilizers that are topdressed.

Research from Virginia Polytechnic Institute shows temperature fluctuations from 20°C up to 40°C and back down to 20°C in a 20-hour period results in significant differences in release between the CRF technologies. In another experiment, the CRFs were held at 40°C for three days in a flask and then were subjected to constant temperatures for two weeks resulting in a much more consistent release between CRF technologies. From these experiments, we can correlate that logically the temperatures on the surface fluctuates more quickly than in the soil. So depending on the technology, some fertilizers will release more as topdressing than when incorporated.

What is the correlation between topdress and incorporation rates? To answer this, I’ll refer to a real life situation. A grower used the same nine-month fertilizer on a crop; some plants were topdressed while others had the CRF incorporated. He followed the recommended rates for each application method on the product’s label. The plants that were topdressed were not performing as well as the plants that had CRFs incorporated. It turns out, the recommended topdress rate amounted to half the quantity of fertilizer per pot as applied with incorporation. Even with technology differences, I have never seen a fertilizer that can produce the same crop with the same soil and irrigation practices with only half the fertilizer.

The question then is why is the topdress rate so different than the incorporation rate? Each grower should consider their unique growing conditions, but the answer may have something to do with the above mentioned research. I encourage each grower to become familiar with the rates used for topdressing compared to the rates used for incorporation at their facility. It is important to follow the recommended rates on CRF labels, but growers should understand the differences between these rates and make any necessary modifications.

Pilon: Just considering the role temperature plays on the release of CRFs, the formulation I choose seems critical to a successful fertility program.

Passchier: It requires an understanding of your production practices and how these practices combined with temperature and leaching influence the release and availability of nutrients from these products.

Pilon: Do I choose a formulation based on an average year or do I pick one based on addressing the fertility needs during the adverse or extreme conditions that are likely to occur?

Passchier: Have you ever seen a normal year? Like many aspects of growing, think the process through. Does it make sense or are you just wishing it works? Growers should understand that there is always a possibility for adverse or extreme conditions. No CRF product can release effectively under all circumstances. A good fertility program will have strategies in place to address these extreme conditions. For example, if unseasonably cool weather has reduced the rate of release, growers can conduct soil tests to determine if the nutrient levels are too low and then apply nutrients through foliar feeding or using water soluble fertilizers. Conversely, with excessive temperatures, growers can monitor the crops, and if the salt levels are climbing, they can reduce them by leaching the crop. CRFs do not replace the need for growers to monitor the nutritional status of their crops and make the necessary adjustments on a regular basis.

Pilon: If a fertilizer specifies a six-month release at 70 degrees, what could I expect at 55 or 85 degrees? How would extended periods of these temperatures affect the release/performance of the fertilizer?

Passchier: Most CRF products provide a table, such as the one shown in Table 1, depicting its longevity at various temperatures. Growers should note that each product and formulation will have its own longevity, even when the NPK values are similar.average temperature is higher than it actually is.same rate, it stands to reason that there will likely not be a sufficient quantity of nutrients left in either of these formulations in the long run.

To best determine a product’s true longevity, the grower needs to know what the average media temperature is throughout production. As mentioned previously, it is difficult to determine the average media temperature. When measuring the media temperature during the summer months, there are often wide temperature fluctuations that often cause growers to assume their average temperature is higher than it actually is.

The temperature at the prill affects the speed at which the fertilizer goes to a semi-soluble state so it can move through the membrane (coating) or the speed at which the prill cracks and lets the fertilizer out so it becomes available plant food.

The bigger question again is how does the rate of the fertilizer affect the feeding of the plant at the temperature you are growing in? When using 10 pounds of 19-5-8 per cubic yard with media temperatures of 60°F, the CRF may possibly have a nine-month longevity, but the amount of fertilizer available to the plant at this temperature will likely be insufficient for plant growth. Conversely, when using 10 pounds of 19-5-8 at 90°F, the amount of fertilizer being released will likely be excessive.

It is not uncommon for competitive CRF products at various longevities to provide similar results at similar rates. For example, I conducted trials using a competitor’s 12- to 14-month product against a five- to six-month formulation with the same amount of product applied per container. In my opinion, both products performed equally well. Achieving equal performance in the short run should cause growers to doubt the longevity of the 12- to 14-month fertilizer and also cause them to question the rate used on the five- to six-month formulation. Logically, if both longevities performed well in the short run at the same rate, it stands to reason that there will likely not be a sufficient quantity of nutrients left in either of these formulations in the long run.

To obtain the best results, growers should utilize formulations that have been developed to fit their geographic area and production temperatures. For example, many growers in the North try to use CRFs developed for production in the South and often do not obtain satisfactory results. CRF formulators can develop blends of fertilizer to match a temperature growing region to help growers optimize the release, longevity and performance for various geographic areas. Unfortunately, when it comes to CRFs, there truly should not be a one-bag-fits-all mentality.

Pilon: What affect do irrigation practices have on the availability of nutrients?

Passchier: The easy answer is everything! Watering practices greatly affect the availability of nutrients to the plant.

Dr. Ted Bilderback at North Carolina State University has done some great research looking at various aspects of irrigation including application timing, methods of delivery, how much to apply and how the architecture of the plant affects the availability of water to the plant. The factors affecting water availability from irrigation practices also affect the availability of nutrients from CRFs. Most importantly, too much irrigation leaches the fertilizer out of the pot and not enough causes the salt levels to build.

As discussed in this series, there are numerous factors and considerations that affect the release of CRFs. Understanding these principles will allow growers to more successfully implement CRFs into production.

Growers should be careful with which formulations they choose, choose an appropriate longevity, use the rates on the products label, have realistic expectations and conduct trials at their facilities to find a formulation that matches their production requirements.

What will be the next big perennial? Breeders say it takes more than a splashy plant to distinguish itself in the market. Therefore, the question is not what will be the next big perennial, but rather what perennial performs well enough in the garden to have staying power in the market for years to come.

The industry's goal is to have loyal customers who return to the same plants time and time again, not because of price, but owing to a plant brand that shouts top-notch garden performance and is synonymous with excellence, which gives them the secure knowledge that their investment will be worth every hard-earned cent.

As growers look for new ways to cut costs and conserve resources, fertilizer and equipment companies are offering products that strive to save water, reduce toxic runoff and keep chemicals out of the equation.

The new 16-4-17 Hydroponic Fertilizer from OASIS Grower Solutions (OGS) is a one-bag solution that replaces two-part systems traditionally used by commercial hydroponic growers. It is specifically formulated for commercial hydroponic production of lettuce, herbs and vegetables.

New fertilizer products not only deliver optimum nutrition, they also provide for easier application and increased efficiency. Check out these new products to help your operation produce a healthy crop in 2014. Click through on the pages below.

EcoVita, a homogeneous granular organic fertilizer, has been added to Bioworks Inc.’s Verdanta biofertilizers product family. This fertilizer will be manufactured and supplied to BioWorks by DCM Corporation of Belgium, a producer of natural and organic-based fertilizers in Western Europe. EcoVita is suitable for a wide variety of crops with its gentle release curve including:• Organic fertilization as a base nutrition in potting mixes• Leafy vegetables• Fruiting vegetables (s a top dressing) • Roses and other ornamentals The new fertilizer offers long-lasting and continuous action for 75 to 100 days and contains organic phosphorus (5 percent P2O5) for fast rooting. Nutrients in EcoVita are gradually released by the soil microbes, in addition to producing humus for better rooting and less leaching. EcoVita is OMRI Listed, making it suitable for use in organic production. “We’re pleased to introduce EcoVita 7-5-10 as our organic NPK product to complement our organic products: K-Vita 2-0-20 […]

Rockwell Farms has introduced Rockwell Farms Plant Food, a bottled liquid fertilizer that does not need to be diluted before use. Always looking for ways to help the consumer succeeed, Jason Roseman of Rockwell Farms says the operation is also always looking for ways to get consumers to come back and buy more plants and flowers. “We feel like fertilization is one of those things that can be very confusing,” Roseman says. “Not everyone does it, and not everyone knows what they’re supposed to do.” The solution: Rockwell Farms Plant Food. The formulation is 150 ppm of a 20-10-20 fertilizer and is sold in 24-ounce bottles. Rockwell recommends that one bottle be used to fertilize 1.5- to 3-gallon outdoor plant and flower containers every 21 days. The product’s signage shows a young patio gardener pouring the bottled fertilizer on a windowbox with the tagline, “Just pour on your way out […]

MGS Horticultural Inc., a full-service supplier of fertilizers, pest control products, seeds and substrates in North America, together with Haifa Chemicals, a global supplier of potassium nitrate for agriculture and industry, specialty plant nutrients and food phosphates, today announced a plan to purchase Canadian fertilizer and pesticides supplier Plant Products Co. Ltd. The deal is anticipated to close by the end of June 2013. MGS will acquire Plant Products’ Canadian distribution business, sales force and name. MGS plans to use both names (MGS Horticultural and Plant Products) in all communications going forward. MGS will maintain locations in Leamington, ON; Brampton, ON; Laval, QC; St. Hyacinthe, QC; and Detroit, Mich. As part of the deal, MGS has signed multi-year agreements with Haifa to maintain exclusive distribution of Plant-Prod Soluble Fertilizers, Acer Controlled Release Fertilizer, Stim-Root and potting soil premix fertilizers for distribution in Saskatchewan, Manitoba and Eastern Canada. “MGS is excited […]

Compared to other variable costs, fertilizers are not the largest part of the budget in conventional greenhouse production. Nevertheless, over the course of the season, mistakes in fertilizer use can lead to significant damages or crop losses. That makes this an important topic for ornamental growers who are experimenting with growing vegetable crops. This article will emphasize major differences between fertilizers used in vegetable production and in ornamentals production. The different nutrition strategies, monitoring and water volume per plant will also be explained. Fertilizer In ornamental production, nutrients are delivered using various water-soluble fertilizers through a fertilizer injector, through the use of controlled-release fertilizers, or a combination of the two. There are numerous fertilizer mixes available with all the needed nutrients already included. The fertilization rate is often given in parts per million (ppm) of nitrogen (N), which is a way of expressing the fertilizer concentration. At younger stages, plants will […]

Ball DPF has announced the launch of Nature’s Source, a rebranding in name and packaging for its seed extract-based plant fertilizer product Daniels Plant Food. The new brand will make its industry debut at California Spring Trials. “While we are proud of our heritage, we made this bold decision because we’re expanding sales to our existing market segments and entering new ones. It was a good opportunity to start with a fresh name and a modern look for all our products and packaging,” says Chance Finch, general manager for Ball DPF. “We wanted to make it obvious, beginning with our Nature’s Source brand name, to know our products are sourced from nature. Growers, contractors and gardeners can be confident that our effective and unique formulations remain unchanged. We’re excited about launching updated packaging for all our products, and especially the new ready-to-spray plant food for home gardeners.” The Nature’s Source brand […]

Everris has introduced its new E-Max Release Technology, a proprietary coating chemistry for use on a wide variety of nutrient components that are incorporated into controlled-release fertilizer products. According to Chris Buchheit, marketing manager for Everris’ ornamental horticulture products, E-Max will help Osmocote and the company’s other existing brands deliver even better performance and value. “This coating will aid in the development of products that both complement and enhance our Osmocote portfolio and other fertilizer lines. It will increase Everris’ flexibility to create customized nutrition programs designed for horticulture growers,” Buchheit says. E-Max Release Technology is a durable, cutting-edge, reacted polymer coating for use on a variety of essential macro- and micronutrients. Nutrients coated with E-Max Technology are produced to the same performance standards as Osmocote. It will allow for continued expansion of the Everris portfolio, the ability to further enhance nutritional values and an efficient use of a grower’s […]

BioSafe Systems has entered into a strategic partnership with Daniels Plant Food Company, a wholly owned subsidiary of Ball Horticulture Inc. BioSafe and Daniels have worked closely together for the past two years and will now look to further develop liquid plant food serving both the conventional and organic markets. In conjunction, BioSafe Systems will be introducing its own branded line of plant food products focusing on turf, landscape and agricultural markets. “Liquid plant food is a natural progression for our company” says Rob Larose, CEO of BioSafe Systems. “It fits perfectly into our current line of green and sustainable products, and we are excited about partnering with Daniels.” Daniels manufactures and markets both conventional and organic liquid fertilizers, using botanical extracts to provide high-value nutrition to plants. BioSafe Systems develops and markets effective and sustainable products to a wide variety of industries, including fruit and vegetable production, turf and […]